Eckle Sidonia B G, Corbett Alexandra J, Keller Andrew N, Chen Zhenjun, Godfrey Dale I, Liu Ligong, Mak Jeffrey Y W, Fairlie David P, Rossjohn Jamie, McCluskey James
From the Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, and.
the Infection and Immunity Program and Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, and Australian Research Council Centre of Excellence in Advanced Molecular Imaging, Monash University, Clayton, Victoria 3800, Australia.
J Biol Chem. 2015 Dec 18;290(51):30204-11. doi: 10.1074/jbc.R115.685990. Epub 2015 Oct 14.
Vitamin B2 (riboflavin) is essential for metabolic functions and is synthesized by many bacteria, yeast, and plants, but not by mammals and other animals, which must acquire it from the diet. In mammals, modified pyrimidine intermediates from the microbial biosynthesis of riboflavin are recognized as signature biomarkers of microbial infection. This recognition occurs by specialized lymphocytes known as mucosal associated invariant T (MAIT) cells. The major histocompatibility class I-like antigen-presenting molecule, MR1, captures these pyrimidine intermediates, but only after their condensation with small molecules derived from glycolysis and other metabolic pathways to form short-lived antigens. The resulting MR1-Ag complexes are recognized by MAIT cell antigen receptors (αβ T cell receptors (TCRs)), and the subsequent MAIT cell immune responses are thought to protect the host from pathogens at mucosal surfaces. Here, we review our understanding of how these novel antigens are generated and discuss their interactions with MR1 and MAIT TCRs.
维生素B2（核黄素）对代谢功能至关重要，可由许多细菌、酵母和植物合成，但哺乳动物和其他动物无法合成，它们必须从饮食中获取。在哺乳动物中，微生物合成核黄素产生的修饰嘧啶中间体被认为是微生物感染的标志性生物标志物。这种识别是由称为黏膜相关恒定T（MAIT）细胞的特殊淋巴细胞进行的。主要组织相容性复合体I类样抗原呈递分子MR1捕获这些嘧啶中间体，但只有在它们与糖酵解和其他代谢途径产生的小分子缩合形成短寿命抗原之后。由此产生的MR1-抗原复合物被MAIT细胞抗原受体（αβT细胞受体（TCR））识别，随后的MAIT细胞免疫反应被认为可保护宿主免受黏膜表面病原体的侵害。在这里，我们回顾了我们对这些新型抗原如何产生的理解，并讨论了它们与MR1和MAIT TCR的相互作用。
